The present invention generally relates to cutting of an ingot and particularly, to an inner peripheral type thin plate blade suitable for cutting a large-diameter ingot of single-crystal semiconductor and a method of producing the blade.
Conventionally, when ICs (integrated circuits) or LSIs (large scale integrated circuits) are produced by using semiconducting materials such as Si, Ge, GaAs, InP, etc., a cutting process of cutting a synthesized single-crystal ingot into wafers is quite vital in determination of production cost, quality and yield. In this known cutting process, a cylindrical ingot is cut into disklike wafers of 0.3 to 0.5 mm in thickness by using an inner peripheral type diamond whetstone, a multiwire, a multiband steel, etc. In view of slicing efficiency, cutting cost and cutting allowance, slicing by an inner peripheral type whetstone has come into commonest use. Generally, in the known inner peripheral type whetstone of FIGS. 1 and 2, a cutting edge 2 constituted by diamond abrasive grains 4 of about 50 .mu.m in diameter and a nickel electrodeposition layer 5 is formed at an inner periphery of an annular metal base 1.
In the known inner peripheral type whetstone, since the diamond abrasive grains 4 subjected to nickel electrodeposition is employed, it is difficult to control thickness of the cutting edge 2 due to electrodeposition. Therefore, the known inner peripheral type whetstone has such drawbacks as wide distribution of thickness of the cutting edge 2, large cutting allowance, separation of the diamond abrasive grains 4 from the cutting edge 2 and wear of the nickel electrodeposition layer 5, thereby resulting in aggravation of its cutting accuracy and service life.